PRIMARY BONE LYMPHOMAS: RETROSPECTIVE ANALYSIS OF 42 CONSECUTIVE CASES.

Objective: It is difficult to define parameters for management and factors associated with primary bone lymphoma (PBL). This article presents the experience in a single institution with 42 patients with PBL over a 16-year period (2000-2016).

Methods: Fifty-five patients were retrospectively evaluated, and forty-two were included (76.3%).

Results: Median age at diagnosis was 51.5 years, and median follow-up was 102.7 months. One patient had HIV. Pain in the affected site was the most prevalent symptom. The average time between symptom onset and diagnosis was 5.4 months. The vertebrae were most affected (n=16, 33.3%). According to the International Prognostic Index Score (IPI), 64.3% of the patients were classified as having low-grade lymphoma and 25.7% as low-intermediate. The most common histology was diffuse large B cell lymphoma (DLBCL) (85.7%). Immunophenotyping was CD20 positive in 93.5% of patients, and 11 patients had pathological fracture. All patients received chemotherapy and 30% of the regimens included rituximab. Thirty-eight percent of patients received radiation therapy. Overall survival was 50%, and survival median time was 80 months. Age and chemotherapy regimen influenced patient survival. Younger patients and patients who received RCHOP had better prognoses.

Conclusions: The choice of chemotherapy regimen associated with age influenced survival for patients with PBL. Level of Evidence IV; Case series.